JPH068330B2 - Polymerization method of tri-substituted silylalkyne - Google Patents

Description

Description: FIELD OF THE INVENTION This invention relates to a method for preparing polymeric tri-substituted silylalkynes that can be cast into membranes from components of a gas mixture and used to separate components of the gas mixture. Regarding improvement.

(Prior Art) Organic solvents and suitable catalysts such as TaC ₅ , MoC ₅ , Nb
The preparation of polymeric tri-substituted silylalkynes with C ₅ or other Group VB or IVB metal halides is well known as the production of polymeric membranes and gas separation processes using said polymeric membranes.

The preparation of treated translucent polymeric membranes consisting of poly (trialkylsilylpropyne) and a polymer having the general structural formula is disclosed in US Pat. No. 4,657,564.

[Wherein R ₁ is a linear or branched C ₁ -C ₄ alkyl group, R ₂ and R ₃ are independent linear or branched C ₁ -C ₆ alkyl groups, and R ₄ is a linear or branched C ₁ -C ₄ alkyl group. A branched C ₁ -C ₁₂ alkyl group or aryl group, X is a C ₁ -C ₃ alkyl group or phenyl, m is at least 100 and n is 0 or 1]. These polymers were prepared with tri-substitution (silylalkynes), the polymerization method of which is incorporated herein by reference.

British Application No. 2,135,319A uses different silipropyne monomers in the presence of halogen compounds of the transition metals of Group VB of the Periodic Table.
One more 1-monoalkyl (C ₁ -C ₁₂₎ discloses polymerization of dimethylsilyl propyne. Organoaluminum formulations are described as cocatalysts.

(Problems to be Solved by the Invention) By combining the effect of the solvent and the temperature with the pentahalide of niobium and tantalum in a toluene solution at a temperature of 80 ° C, 1-
Polymerization of (trimethylsilyl) -1-propyne was described by T. Matsuda et al.
1- (Trimethylsilyl) -1-propyne, Bi, Harize, Of, Nioubiam (V) And, Tantalum (V), And, Polymer, Properties "Polymeriza
tion of 1- (trimethylsilyl) -1-propy-ne by Halid
es of Niobium (V) and Tantalum (V) and polymer P
"Polymer" Vol. 18, No. 5 (1985)
It is described in the article on pages 841 to 845.

Catalysis of polymerization of sterically blocked acetylene and dialkylacetylene in solvent with molybdenum and other methyl halides.
T. Matsuda et al. “Polymerization,
Of, Methyl Pentins, Buy, Transition, Metal, Catalysts: Monomer, Structure, Reactivity, And, Polymer, Properties (Polymer
ization of Methylpentynes by Transition Metal cata
-lysts: Monomer Structure, Reactivity, and Polymer Pr
operties) entitled "Polymer, Journal" (Polyme
r journal) Vol. 4, No. 5 (1982), pages 371 to 377.

"Synthesis, High, Polymers, Frome, Substituted, Acetylenes: Exploitation, Of, Molybdenum, And, Tungsten-based, Catalyst" (Synthesis of High Polym)
ers from Substitut-ed Acetylenes: Exploitation of M
Olybdenum and Tungsten−Based Catalysts)
C. Chem. Res. 17 (1984) 51-56, T. Matsuda discloses polymerization of aromatic and aliphatic acetylenes.

This invention relates to the polymerization rate and conversion of tri-substituted silylalkynes, especially trimethylsilylpropyne, in the presence of a Group VB or VIB metal halide catalyst based on the total alkyne concentration of about 0.1 to about 10% of the trialkylgermyl alkyne compound.
It is based on the finding that it can be increased by using 5.0 mol%. The reaction is carried out at the polymerization temperature typical of such reactions, preferably in the presence of a suitable organic solvent.

The main purpose of this invention is US Pat. No. 4,657,56
It is an object of the present invention to provide an improved method for preparing polymeric tri-substituted silylalkynes useful for casting gas component separation into a membrane structure described in Example of No. 4.

This and other objects and advantages of the invention will be apparent from the description of the invention and the claims that follow.

(Means for Solving the Problems) A tri-substituted silylalkyne polymer having the following general structural formula according to the present invention is added in an organic solvent solution at about 30 ° C. to about 100 ° C.
C., preferably about 50.degree. C. to about 100.degree. C., more preferably about VB or VIB metal halide catalyst and about a trialkylgermyl alkyne compound based on total alkyne concentration.
It is produced at a polymerization temperature of 70 ° C to 90 ° C in the presence of 0.1 to 5.0 mol%: [Wherein R ₁ is a linear or branched C ₁ -C ₄ alkyl group, R ₂ and
R ₃ is an independent linear or branched C ₁ -C ₆ alkyl group, R ₄ is a linear or branched C ₁ -C ₁₂ alkyl group or aryl group, X
Is a C ₁ -C ₃ alkyl group or phenyl, m is at least 100
N is 0 or 1].

(Function) In general, the polymerization rate of a tri-substituted silyl alkyne such as trimethylsilyl propyne depends on the charging process parameters of the polymerization temperature (Tp) and the ratio of the catalyst to the monomer (C / M). Increasing the polymerization rate with prior art processing equipment can either increase the polymerization temperature or increase the ratio of catalyst to monomer. Increasing the Tp or (and) C / M ratio will increase the rate of polymerization, but will result in a decrease in the molecular weight and intrinsic viscosity of the resulting polymer. An increase in both the Tp and C / M ratio also results in a decrease in the polymer molecular weight.

It is known that the conversion of polymers of trisubstituted silylalkynes such as trimethylsilylpropyne in the presence of Group V or VI metal halide catalysts is very sensitive to monomer purity. Agents that act as trace amounts of chain terminators (eg ethers, alcohols) also significantly reduce the yield of monomers if they do not interfere with the polymerization. By way of illustration, the polymerization of high-purity trimethylsilylpropyne (TMSP) in the presence of catalytic amounts of tantalum (V) chloride is almost quantitative. However, in the presence of trace amounts of foreign matter, such as 0.5%, such as tetrahydrafuran (THF), the yield of polytrimethylsilylpropyne is reduced by at least 15%. The amount of 1.0% THF completely prevents the polymerization of TMSP.

Such stringent requirements for monomer purity require time-consuming and often expensive purification procedures. In some cases, the removal of all traces of impurities harmful to the body is just not possible, especially when its boiling point is close to that of the monomer. In such a situation, the yield of monomer will decrease as the amount of residual foreign material increases.

Both the polymerization rate and the conversion of tri-substituted silylalkynes are significantly increased by the addition of a small amount, based on the total alkyne concentration, of about 0.1 to 5.0 mol% of the trialkylgermyl alkyne compound. The trialkylgermyl alkyne compound added to the polymerization mixture can be any compound having the following general structural formula.

(In the formula, R ₁ is H or C ₁ -C ₂ alkyl group, R ₂ and R ₃ are independent linear or branched C ₁ -C ₆ alkyl group, R ₄ is linear or branched C ₁ -C ₆ alkyl or aryl groups, X is a C ₁ -C ₃ alkyl group or phenyl, and n is 0 or 1).

The trialkylgermyl alkyne compound may be added independently to the reaction mixture, although in the preferred embodiment it is first mixed with the silyl alkyne monomer and the mixture added to the catalyst and solvent system. . The minimum concentration of germyl alkyne that needs to be added to significantly increase polymerization rate and monomer conversion is very low. That is to say about 0.1 mol% based on the total alkyne concentration. The increase in the concentration of germyl alkyne is the highest conversion (ie 100
%) Is reached at a relatively low concentration, typically less than 5 mol%, even if very low. Moreover, when the germyl alkyne compound is incorporated into the polymer chain and the resulting polymer is predominantly a poly (silylalkyne) polymer rather than a copolymer, the amount of germyl additive should be small. It is better to keep it.

The exact mechanism by which the trialkylgermyl alkyne compound accelerates polymerization and further enhances monomer conversion is still not well defined. However, without being bound by theory, the first step in Group V or VIB metal halide promoted trialkylsilylene polymerization is to combine the monomer with 1 molar equivalent of metal to form a highly reactive intermediate. Conceivable. Then, this intermediate is further reacted with the residual monomer to form a polymer chain. Certain monomeric impurities, especially ethers and alcohols, can compete well for monomers that react in the core of the metal. The specificity of the germylin monomer lies in its obvious tendency to react rapidly with metal halide salts to form this reactive intermediate. In the presence of a germylin additive, then preferably trimethylgermylpropyne, the formation of said reactive intermediates is quantitative until now the formation of said reactive intermediates is not adversely affected by body-damaging impurities.

The polymerization procedure can be any suitable technique as described in the techniques cited above. The improvement achieved by the addition of the Germyl alkyne formulation of the above structural formula can be achieved using any type of processing conditions, including temperature and pressure. As with prior art methods, the method of the present invention is preferably carried out in the presence of an organic solvent.

The organic solvent used in the present invention is stable and chemically inert to this polymerization method, and is, for example, benzene, toluene, xylene, chlorobenzenes, nitrobenzenes, nitrotoluenes, bromobenzenes and the like. It may be any aromatic or substituted aromatic hydrocarbon solvent including. Toluene is the preferred solvent for this polymerization scheme.

Experiments were conducted to demonstrate the unique effect of trialkylgermyl alkyne compounds on the conversion of trimethylsilylpropyne and on the resulting polymer molecular weight. These examples are provided to illustrate the invention in accordance with the principles of the invention and include specific features of the invention. However, these examples should not be construed as limiting the invention in any way, and many modifications can be made without departing from the spirit and scope of the invention.

Examples Example 1 A series of tests were performed in which the close ties mainly found in the commercially available trimethylsilylpropyne (TMSP). Hexamethyldisiloxane, a close boili-ng impurity, was added to the high purity TMSP material in various amounts. A test was also conducted in which tetrahydrofuran (THF) was added to high-purity TMSP. Containing various concentrations of impurities
TMSP monomers were polymerized in the presence of a Group V or VI metal halide catalyst according to the general procedure detailed in British Patent Application No. 2135319A. Polymerization was performed using TMSP with added impurities and trimethylgermylpropyne (TMGP).
Performed alone to provide a direct comparison of the effect of addition of trialkylgermylpropyne compound on the monomer in the presence of trace impurities. The results of these tests are reported in Table 1 below.

The above results show that when hexamethyldisiloxane (HMDS) foreign matter is present with the TMSP, the decrease in polymer yield is 1.5%.
It was observed with a low amount of foreign matter (0.015 molar equivalent).
A significant reduction in foreign material concentration as low as 5.0% is observed.
However, when the TMSP sample contained TMGP as well as HMDS, polymerization was quantitative for all amounts of impurities tested. Only a concentration of 0.5% THF reduced the yield of polymer, but the coexistence of THF and TMGP resulted in a slight reduction in TMSP yield.

Example 2 A test was conducted to polymerize a commercial grade TMSP monomer from Petrach Chemical Co. Polymerization was carried out in the presence of a catalyst prepared by dissolving 0.01 molar equivalent of tantalum (V) chloride in toluene at room temperature in an inert atmosphere. Polymerization took place within seconds when the monomer was added to the catalyst solution. The polymer was processed in methanol, redissolved in toluene, reprecipitated with methanol and dried in vacuo overnight at room temperature. The molecular weight of the polymer was measured by the intrinsic viscosity. Testing was performed according to this procedure using a 98: 2 mixture of commercial TMSP monomer and trimethylgermyl propyne. The results of these tests are reported in Table 2 below.

The results reported in Table 2 indicate that the molecular weight of the only TMSP polymer was higher than that of the TMSP: TMGP mixture, while the product yield was significantly lower. These results further point out that small amounts of TMGP have a considerable effect on the addition (yield) of such polymerization reactions.

Studies were conducted on the permeability and gas separation retention properties of the resulting polymer-fabricated membranes as well as physical properties such as tensile strength of the polymers. In each of these tests, the properties of the polymer were not considered to be adversely affected by the presence of small amounts of germanium in the structure of the polymer and therefore the polymer was used for PTMSP in any commercial application. It is better to use instead of a homopolymer.

Example 3 Several tests were conducted to determine the effect of TMGP on the polymerization rate of TMSP. The polymerization reaction was carried out in toluene using TaC ₅ catalyst. Polymerization times of various TMSP: TMGP mixtures were measured and the results are reported in Table 3 below.

Table 3 Mol% TMSP: TMGP Polymerization time ^* (seconds) 100: 0 15,000 98: 2 33 95: 5 16 ^* Time required to reach a gel state where stirring becomes difficult (effect of the invention) From the above polymerization results As can be seen, the presence of TMGP, even in small amounts, significantly accelerates the polymerization. This rapid polymerization enables in-situ synthesis of thin film polymers, which is extremely difficult to make when using only TMSP monomers.

The above results show that traces of TMGP dramatically accelerate the polymerization of TMSP and can also be used as an additive to improve the conversion of impure TMSP to PTMSP. The method of the present invention provides a suitable alternative to expensive monomer purification procedures as impurities can be entrained throughout the polymerization process without adversely affecting product yield. The impurities can therefore be easily separated from the resulting polymer by washing with methanol. As previously mentioned, the incorporation of such small amounts of trimethylgermyl propyne into the polymer structure does not significantly change the properties of said polymer. Therefore, this technique is applicable to the polymerization of all ein monomers in the presence of V or VIB metal halides.

Although the method of this invention is primarily concerned with the polymerization of trimethylsilylpropyne in the presence of TaC ₅ , it is not intended that this method be limited to any particular silylalkyne or metal halide and those skilled in the art will appreciate that Widely applicable to the polymerization of other Group VB or VIB metal halides as well as other tri-substituted silyl alkynes in the formulas described above in the specification, other polymeric silyl alkynes such as polymeric triethylsilyl propyl, trimethyl silyl butyl. It permits the production of other products of the same type.

Claims (8)

[Claims] 1. A tri-substituted silylalkyne is a VB or VI.
A method for producing a polymer having the following general structural formula by polymerizing in an organic solvent in the presence of a Group B metal halide catalyst, wherein the amount of trialkylgermylalkyne compound is 0.1 to 5.0 mol% based on the total alkyne concentration, A polymerization process comprising increasing the conversion and the rate of polymerization of tri-substituted silylalkynes comprising conducting the polymerization. (In the formula, R ₁ is a linear or branched C ₁ -C ₄ alkyl group,
R ₂ and R ₃ are independent linear or branched C ₁ -C ₆ alkyl groups,
R ₄ is a linear or branched C ₁ -C ₁₂ alkyl group or aryl group, X is a C ₁ -C ₃ alkyl group or phenyl, m is at least 100 and n is 0 or 1). 2. The trialkylgermyl alkyne compound has the following general structural formula:
Polymerization of tri-substituted silylalkynes by. (In the formula, R ₁ is H or a C ₁ -C ₁₂ alkyl group, R ₂ and R ₃
Is an independent linear or branched C ₁ -C ₆ alkyl group, R ₄ is a linear or branched C ₁ -C ₆ alkyl or aryl group, X
The C ₁ -C ₃ alkyl or phenyl and n is 0 or 1). 3. The method for polymerizing a tri-substituted silylalkyne according to claim 2, wherein the trialkylgermyl alkyne is trimethylgermyl propyne. 4. The method for polymerizing a tri-substituted silylalkyne according to claim 2, wherein n in the general structural formula is 0. 5. The method for polymerizing a tri-substituted silyl alkyne according to claim 1, wherein the tri-substituted silyl alkyne is trimethyl silyl propyne. 6. The method of polymerizing a tri-substituted silylalkyne according to claim 1, wherein the metal halide catalyst is TaCl ₅ . 7. The method for polymerizing a tri-substituted silylalkyne according to claim 1, wherein the polymerization is carried out at a temperature of 30 ° C. to 100 ° C. 8. The method of polymerizing a tri-substituted silylalkyne according to claim 1, wherein the organic solvent is toluene.